[math-fun] Limit question

The expression f(n) = sqrt(1 + sqrt(2 + . . . + sqrt(n)...)) approaches about 1.7579 . Rather quickly, too: For n >= 20, the first 16 digits after the decimal point remain the same. Is there a closed form for lim n->oo f(n) ? --Dan _____________________________________________________________________ "It don't mean a thing if it ain't got that certain je ne sais quoi." --Peter Schickele